CN115667365A

CN115667365A - Polyamide resin, polyamide resin composition, and molded article

Info

Publication number: CN115667365A
Application number: CN202180038587.3A
Authority: CN
Inventors: 大塚浩介; 冈岛裕矢
Original assignee: Mitsubishi Gas Chemical Co Inc
Current assignee: Mitsubishi Gas Chemical Co Inc
Priority date: 2020-05-29
Filing date: 2021-05-24
Publication date: 2023-01-31
Anticipated expiration: 2041-05-24
Also published as: EP4159788A1; TW202208503A; CN115667365B; US20230235121A1; KR20230017852A; JPWO2021241471A1; WO2021241471A1; EP4159788A4

Abstract

Provided are a polyamide resin having a high melting point and a high glass transition temperature, a polyamide resin composition, and a molded article. A polyamide resin comprising a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, wherein 50 mol% or more of the diamine-derived structural unit is a structural unit derived from p-phenylenediamine, and 65 mol% or more of the dicarboxylic acid-derived structural unit is a structural unit derived from an aromatic dicarboxylic acid.

Description

Polyamide resin, polyamide resin composition, and molded article

Technical Field

The present invention relates to a polyamide resin. In particular to a novel polyamide resin with high melting point and glass transition temperature. Also disclosed are a resin composition and a molded article each comprising such a polyamide resin.

Background

Polyamide resins are widely used as various industrial materials from the viewpoint of their excellent processability, durability, heat resistance, gas barrier properties, chemical resistance, and the like.

As such a polyamide resin, aliphatic polyamide resins typified by polyamide 6 and polyamide 66 have been used since now. Further, an aromatic polyamide resin in which an aromatic dicarboxylic acid and/or an aromatic diamine is used as a raw material of a polyamide resin has been also used. Such aromatic polyamide resins are described in, for example, patent documents 1 and 2.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 62-054725

Patent document 2: japanese patent laid-open publication No. H08-003312

Disclosure of Invention

Problems to be solved by the invention

As described above, polyamide resins are widely used in various fields. Among them, with the technological innovation, there is a demand for polyamide resins having more excellent heat resistance. In particular, polyamide resins having high melting points and glass transition temperatures are required.

The present invention is to solve the above problems, and an object of the present invention is to: provided are a polyamide resin having a high melting point and a high glass transition temperature, and a polyamide resin composition and a molded article using the same.

Means for solving the problems

Based on the above problems, the present inventors have studied and found that: the above problems can be solved by using p-phenylenethylamine and an aromatic dicarboxylic acid in amounts of at least a certain amount as raw material monomers of a polyamide resin.

Specifically, the above problems are solved by the following means.

< 1 > a polyamide resin comprising a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, wherein 50 mol% or more of the diamine-derived structural unit is a structural unit derived from p-phenylenediamine, and 65 mol% or more of the dicarboxylic acid-derived structural unit is a structural unit derived from an aromatic dicarboxylic acid.

< 2 > the polyamide resin according to < 1 >, wherein more than 95 mol% of the aforementioned structural units derived from a dicarboxylic acid are structural units derived from an aromatic dicarboxylic acid.

< 3 > the polyamide resin according to < 2 >, wherein 90 mol% or more of the structural units derived from an aromatic dicarboxylic acid are structural units derived from an aromatic dicarboxylic acid selected from the group consisting of isophthalic acid, terephthalic acid and phenylenediacetic acid.

< 4 > the polyamide resin according to < 2 >, wherein 90 mol% or more of the structural units derived from an aromatic dicarboxylic acid are structural units derived from an aromatic dicarboxylic acid selected from isophthalic acid and phenylenediacetic acid.

< 5 > the polyamide resin according to < 1 >, wherein 65 to 97 mol% of the structural units derived from a dicarboxylic acid are structural units derived from an aromatic dicarboxylic acid, and 3 to 35 mol% are structural units derived from an alicyclic dicarboxylic acid.

< 6 > the polyamide resin according to < 1 >, wherein 75 to 97 mol% of the structural units derived from a dicarboxylic acid are structural units derived from an aromatic dicarboxylic acid, and 3 to 25 mol% are structural units derived from an alicyclic dicarboxylic acid.

< 7 > the polyamide resin according to < 5 > or < 6 >, wherein 90 mol% or more of the structural units derived from an alicyclic dicarboxylic acid are structural units derived from an alicyclic dicarboxylic acid represented by the following Formula (FA).

Formula (FA)

HOOC-(CH ₂ ) _n -alicyclic structure- (CH) ₂ ) _n -COOH

(in the Formula (FA), n represents 0, 1 or 2.)

< 8 > the polyamide resin according to < 5 > or < 6 >, wherein 90 mol% or more of the alicyclic dicarboxylic acid-derived structural units are cyclohexane dicarboxylic acid-derived structural units.

< 9 > the polyamide resin according to < 5 > or < 6 >, wherein 90 mol% or more of the alicyclic dicarboxylic acid-derived structural units are structural units derived from a mixture of trans-form cyclohexanedicarboxylic acid and cis-form cyclohexanedicarboxylic acid.

< 10 > the polyamide resin according to any one of < 1 > to < 9 >, wherein more than 95 mol% of the diamine-derived structural unit and the dicarboxylic acid-derived structural unit are structural units having a cyclic structure.

< 11 > the polyamide resin according to any one of < 1 > to < 10 >, wherein the polyamide resin has a melting point of 300 ℃ or higher as measured by differential scanning calorimetry.

< 12 > the polyamide resin according to any one of < 1 > to < 11 >, wherein the polyamide resin has a glass transition temperature of 100 ℃ or higher as measured by differential scanning calorimetry.

< 13 > a resin composition comprising the polyamide resin as defined in any one of < 1 > -to < 12 >.

< 14 > the resin composition according to < 13 > further comprising an antioxidant.

< 15 > the resin composition according to < 14 > wherein the aforementioned antioxidant comprises a primary antioxidant and a secondary antioxidant.

< 16 > the resin composition according to < 14 > or < 15 > wherein the aforementioned antioxidant comprises an inorganic antioxidant.

< 17 > the resin composition according to any one of < 13 > < 16 >, which further comprises a flame retardant.

< 18 > the resin composition according to any one of < 13 > -17 >, which further comprises a nucleating agent.

< 19 > a molded article comprising the resin composition as defined in any one of < 13 > to < 18 >.

ADVANTAGEOUS EFFECTS OF INVENTION

The present invention can provide a polyamide resin having a high melting point and a high glass transition temperature, a polyamide resin composition, and a molded article.

Detailed Description

Hereinafter, a mode for carrying out the present invention (hereinafter, simply referred to as "the present embodiment") will be described in detail. The following embodiments are merely examples for illustrating the present invention, and the present invention is not limited to the embodiments.

In the present specification, "to" is used in a meaning including numerical values described before and after the "to" as a lower limit value and an upper limit value.

In the present specification, unless otherwise specified, various physical property values and characteristic values are set at 23 ℃.

When the measurement method or the like differs depending on the year, the standard shown in the present specification should be based on the standard at a time point of 5/29/2020 unless otherwise specified.

The polyamide resin of the present embodiment is characterized by being composed of a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, wherein 50 mol% or more of the diamine-derived structural unit is a structural unit derived from p-phenylenediamine, and 65 mol% or more of the dicarboxylic acid-derived structural unit is a structural unit derived from an aromatic dicarboxylic acid. By forming such a structure, a polyamide resin having a high melting point and a high glass transition temperature can be obtained. In addition, the mass reduction rate can be reduced, and the thermal stability during molding can be improved. Further, the enthalpy change (Δ H) of cooling crystallization can be increased, and the moldability can be improved. Examples of the improvement of moldability include: the molding cycle can be shortened because the mold is easily crystallized during injection molding. Also, the amount of air leakage can be reduced.

In the polyamide resin of the present embodiment, the proportion of the structural unit derived from p-phenylenediethylamine in the structural unit derived from a diamine is 50 mol% or more, preferably 60 mol% or more, more preferably 70 mol% or more, further preferably 80 mol% or more, further preferably 90 mol% or more, further preferably 94 mol% or more, and may be 96 mol% or more, 98 mol% or 99 mol% or more. By setting the lower limit value or more, the temperature-decreasing crystallization enthalpy change (Δ H) can be increased, and the moldability tends to be improved. The upper limit of the proportion of the structural unit derived from p-phenylenediethylamine in the structural unit derived from diamine is 100 mol%.

The polyamide resin of the present embodiment may contain, as a diamine-derived structural unit, a structural unit derived from another diamine other than the structural unit derived from p-phenylenediamine. As such other structural units, there can be exemplified: m-phenylenediethylamine, o-phenylenediethylamine, aliphatic diamine, alicyclic diamine, and aromatic diamine other than phenylenediethylamine, with m-phenylenediethylamine being preferred.

The polyamide resin of the present embodiment may contain only 1 structural unit derived from another diamine, or may contain 2 or more kinds.

In the case where the polyamide resin of the present embodiment includes a structural unit derived from m-phenylenediethylamine as a structural unit derived from a diamine, the structural unit derived from p-phenylenediethylamine is 70 to 99 mol% (preferably 80 mol% or more, more preferably 90 mol% or more, and further preferably 93 mol% or more), and the structural unit derived from m-phenylenediethylamine is preferably 1 to 30 mol% (preferably 20 mol% or less, more preferably 10 mol% or less, and further preferably 7 mol% or less).

As the aliphatic diamine, a known aliphatic diamine can be widely used, and preferred is an aliphatic diamine having 6 to 12 carbon atoms, and examples thereof include: 1,6-hexanediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine; branched aliphatic diamines such as 2-methyl-1,8-octanediamine, 4-methyl-1,8-octanediamine, 5-methyl-1,9-nonanediamine, 2,2,4-/2,4,4-trimethylhexamethylenediamine, 2-methyl-1,5-pentanediamine, 2-methyl-1,5-pentanediamine, 2-methyl-1,6-hexanediamine, and 2-methyl-1,7-heptanediamine.

As the alicyclic diamine, known alicyclic diamines can be widely used, and examples thereof include: 1,2-bis (aminomethyl) cyclohexane, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, isophorone diamine, 4,4 '-thiobis (cyclohexane-1-amine), 4,4' -thiobis (cyclohexane-1-amine), and the like.

As for other aromatic diamines, reference may be made to the description in paragraph 0052 of International publication No. 2017/126409, which is incorporated herein.

In the polyamide resin of the present embodiment, the proportion of the structural unit derived from an aromatic dicarboxylic acid in the structural unit derived from a dicarboxylic acid is 65 mol% or more. By setting the lower limit value or more, a polyamide resin having a higher melting point and a higher glass transition temperature tends to be obtained.

In the polyamide resin of the present embodiment, the proportion of the structural unit derived from an aromatic dicarboxylic acid in the structural unit derived from a dicarboxylic acid is 65 mol% or more, preferably 70 mol% or more, more preferably 75 mol% or more, further preferably 80 mol% or more, further preferably 90 mol% or more, further preferably 94 mol% or more, and may be 96 mol% or more, 98 mol% or 99 mol% or more depending on the application. The upper limit may be 100 mol% or less depending on the application.

The polyamide resin of the present embodiment may contain only 1 structural unit derived from an aromatic dicarboxylic acid, or may contain 2 or more types. When 2 or more species are contained, the total amount is preferably within the above range.

A preferable example of the aromatic dicarboxylic acid of the present embodiment is benzenedicarboxylic acid.

Another preferred example of the aromatic dicarboxylic acid of the present embodiment is an aromatic dicarboxylic acid represented by Formula (FC).

Formula (FC)

HOOC-(CH ₂ ) _m -aromatic ring structure- (CH) ₂ ) _m -COOH

(in the Formula (FC), m represents 0, 1 or 2.)

m is preferably 0 or 1, and more preferably 0.

In Formula (FC), the aromatic ring structure is a structure including an aromatic ring, and preferably a structure composed of only an aromatic ring or a structure composed of only an aromatic ring and a substituent thereof, and more preferably a structure composed of only an aromatic ring. Examples of the substituent which the aromatic ring may have include an alkyl group having 1 to 3 carbon atoms and a halogen atom.

The aromatic ring structure may be any of a single ring or a condensed ring, and is preferably a single ring. The number of carbon atoms constituting the aromatic ring is not particularly limited, and a 4-to 15-membered ring is preferred.

More specifically, the aromatic ring structure is preferably a benzene ring, a naphthalene ring, or a substituent on these rings, and more preferably a benzene ring or a substituent on a benzene ring.

More specifically, in the present embodiment, as the aromatic dicarboxylic acid, there can be exemplified: isophthalic acid, terephthalic acid, phthalic acid, phenylenediacetic acid (orthophthalic acid, terephthallic acid, isophthallic acid), naphthalene dicarboxylic acid (1,2-naphthalenedicarboxylic acid, 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 1,7-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid).

Among them, preferred is a compound selected from isophthalic acid, terephthalic acid and phenylenediacetic acid, more preferred is isophthalic acid and phenylenediacetic acid, and still more preferred is isophthalic acid. In particular, it is preferable that 90 mol% or more, more preferably 95 mol% or more, still more preferably 98 mol% or more, and still more preferably 99 mol% or more of the aromatic dicarboxylic acid is the aromatic dicarboxylic acid.

In particular, by using isophthalic acid, the enthalpy change (Δ H) of temperature-decreasing crystallization can be increased, and the moldability can be improved. In addition, the rate of mass reduction may be reduced.

On the other hand, when the phenylenediacetic acid is used in the polyamide resin of the present embodiment, it is preferable that the phenylenediacetic acid is contained in an amount of 50 to 100 mol% and 50 to 0 mol% based on the phenylenediacetic acid.

Next, preferred embodiments of the structural unit derived from a dicarboxylic acid in the polyamide resin of the present embodiment will be described.

The 1 st preferred embodiment of the structural unit derived from a dicarboxylic acid is as follows: more than 95 mol% of the structural units derived from a dicarboxylic acid are structural units derived from an aromatic dicarboxylic acid. When more than 95 mol% of the structural units derived from a dicarboxylic acid are composed of an aromatic dicarboxylic acid, the mass reduction rate can be reduced while maintaining a high melting point and a high glass transition temperature. Further, the change in enthalpy of crystallization (Δ H) at reduced temperature tends to be increased, and the moldability tends to be further improved. Also, the amount of air leakage can be reduced.

In the 1 st preferred embodiment of the dicarboxylic acid-derived structural unit, the proportion of the aromatic dicarboxylic acid-derived structural unit in the dicarboxylic acid-derived structural unit is preferably 96 mol% or more, more preferably 97 mol% or more, further preferably 98 mol% or more, and further preferably 99 mol% or more. By setting the lower limit value or more, the temperature-decreasing crystallization enthalpy change (Δ H) can be increased, and the moldability tends to be further improved. The upper limit of the proportion of the structural unit derived from an aromatic dicarboxylic acid in the structural unit derived from a dicarboxylic acid may be 100 mol%.

In the 1 st preferred embodiment of the dicarboxylic acid-derived structural unit, the aromatic dicarboxylic acid is preferably an aromatic dicarboxylic acid represented by the above Formula (FC), more preferably selected from isophthalic acid, terephthalic acid and phenylenediacetic acid, even more preferably isophthalic acid and/or phenylenediacetic acid, and even more preferably isophthalic acid. In particular, it is preferable that 90 mol% or more, more preferably 95 mol% or more, still more preferably 98 mol% or more, and still more preferably 99 mol% or more of the structural units derived from the aromatic dicarboxylic acid be structural units derived from the aromatic dicarboxylic acid.

In the 1 st preferred embodiment of the structural unit derived from a dicarboxylic acid, in the case of using phenylenediacetic acid, the aromatic dicarboxylic acid preferably contains 50 to 100 mol% of phenylenediacetic acid and 50 to 0 mol% of isophthalodine acid. The total of p-phenylenediacetic acid and m-phenylenediacetic acid is 100 mol% or less, preferably 97 to 100 mol%, of the total dicarboxylic acid-derived structural units.

In the polyamide resin of the present embodiment, the 2 nd preferred embodiment of the structural unit derived from a dicarboxylic acid is as follows: 65 to 97 mol% of the structural units derived from dicarboxylic acid are structural units derived from aromatic dicarboxylic acid, and 3 to 35 mol% are structural units derived from alicyclic dicarboxylic acid. The total of the structural units derived from the aromatic dicarboxylic acid and the structural units derived from the alicyclic dicarboxylic acid is 100 mol% or less, preferably 97 to 100 mol%, of the total of the structural units derived from the dicarboxylic acid.

In the 2 nd preferred embodiment of the dicarboxylic acid-derived structural unit, the dicarboxylic acid-derived structural unit is composed of an aromatic dicarboxylic acid and an alicyclic dicarboxylic acid. By forming such a structure, it is possible to maintain a high melting point and a high glass transition temperature and reduce the mass reduction rate. Further, the temperature-decreasing crystallization enthalpy change (Δ H) can be increased, and the moldability tends to be further improved. Also, the amount of air leakage can be reduced.

In the 2 nd preferred embodiment of the dicarboxylic acid-derived structural unit, the proportion of the aromatic dicarboxylic acid in the dicarboxylic acid-derived structural unit is 65 mol% or more, preferably 70 mol% or more, more preferably 75 mol% or more, further preferably 80 mol% or more, further preferably 85 mol% or more, and still further preferably 88 mol% or more. By setting the lower limit value or more, a polyamide resin having a higher melting point and a higher glass transition temperature tends to be obtained. The proportion of the aromatic dicarboxylic acid in the dicarboxylic acid-derived structural unit is 97 mol% or less, preferably 96 mol% or less, and may be 94 mol% or less, or 92 mol% or less. When the amount is equal to or less than the upper limit, the mass reduction rate can be reduced, and the thermal stability during molding tends to be further improved.

In the 2 nd preferred embodiment of the dicarboxylic acid-derived structural unit, the proportion of the alicyclic dicarboxylic acid in the dicarboxylic acid-derived structural unit is 3 mol% or more, preferably 4 mol% or more, and may be 6 mol% or more and 8 mol% or more. By setting the lower limit value or more, the mass reduction rate can be further reduced, and the thermal stability during molding tends to be further improved. The proportion of the alicyclic dicarboxylic acid in the dicarboxylic acid-derived structural unit is 35 mol% or less, preferably 30 mol% or less, more preferably 25 mol% or less, still more preferably 20 mol% or less, still more preferably 15 mol% or less, and yet more preferably 12 mol% or less. By setting the upper limit value or less, the temperature-decreasing crystallization enthalpy change (Δ H) can be further increased, and the moldability can be further improved. In particular, by setting the proportion of the alicyclic dicarboxylic acid-derived structural unit in the dicarboxylic acid-derived structural unit to 8 to 12 mol%, a high melting point, a high glass transition temperature, a high Δ H, a low mass reduction rate, and low gas leakage can be achieved in a well-balanced manner.

In the 2 nd preferred embodiment of the dicarboxylic acid-derived structural unit, the aromatic dicarboxylic acid is preferably an aromatic dicarboxylic acid represented by the above Formula (FC), more preferably selected from isophthalic acid, terephthalic acid and phenylenediacetic acid, even more preferably isophthalic acid and phenylenediacetic acid, and even more preferably isophthalic acid. In particular, it is preferable that 90 mol% or more, more preferably 95 mol% or more, still more preferably 98 mol% or more, and still more preferably 99 mol% or more of the aromatic dicarboxylic acid is the aromatic dicarboxylic acid. The upper limit is 100 mol%.

In the 2 nd preferred embodiment of the dicarboxylic acid-derived structural unit, the alicyclic dicarboxylic acid is not particularly limited, and a known alicyclic dicarboxylic acid can be used. Specifically, the following can be exemplified: alicyclic dicarboxylic acids having 6 to 20 carbon atoms. The alicyclic dicarboxylic acid is preferably an alicyclic dicarboxylic acid represented by the Formula (FA), and more preferably cyclohexanedicarboxylic acid (preferably a mixture of trans-form cyclohexanedicarboxylic acid and cis-form cyclohexanedicarboxylic acid). In particular, it is preferable that 90 mol% or more, more preferably 95 mol% or more, still more preferably 98 mol% or more, and still more preferably 99 mol% or more of the alicyclic dicarboxylic acid is the alicyclic dicarboxylic acid. The upper limit is 100 mol%.

Formula (FA)

HOOC-(CH ₂ ) _n -alicyclic structure- (CH) ₂ ) _n -COOH

(in the Formula (FA), n represents 0, 1 or 2.)

n is preferably 0 or 1, and more preferably 0.

The alicyclic structure is a structure containing an alicyclic group, and is preferably a structure composed of only an alicyclic group or a structure composed of only an alicyclic group and a substituent thereof, and more preferably a structure composed of only an alicyclic group. Examples of the substituent that the alicyclic structure may have include an alkyl group having 1 to 3 carbon atoms and a halogen atom.

The alicyclic structure may be any of a single ring or a condensed ring, and is preferably a single ring. The number of carbon atoms constituting the ring is not particularly limited, and a 4-to 10-membered ring is preferred.

In the 2 nd preferred embodiment of the structural unit derived from a dicarboxylic acid, the alicyclic structure is preferably a cyclohexane ring.

In the 2 nd preferred embodiment of the dicarboxylic acid-derived structural unit, the cyclohexanedicarboxylic acid may be either a cis-isomer or a trans-isomer, and is preferably a mixture of a trans-isomer cyclohexanedicarboxylic acid and a cis-isomer cyclohexanedicarboxylic acid. By using the mixture, a polyamide resin having a higher glass transition temperature can be obtained, and the mass reduction rate can be further reduced.

Cyclohexanedicarboxylic acid is more preferably 1,4-cyclohexanedicarboxylic acid and/or 1,3-cyclohexanedicarboxylic acid, and even more preferably 1,4-cyclohexanedicarboxylic acid. By using such a compound, the mass reduction rate can be further reduced, and the thermal stability during molding can be further improved.

As the alicyclic dicarboxylic acid usable in the 2 nd preferred embodiment of the structural unit derived from a dicarboxylic acid, specifically, in addition to the above, there can be exemplified: 4,4 '-methylenebis (2-methylcyclohexane-1-carboxylic acid), 4,4' -methylenebis (cyclohexane-1-carboxylic acid), 4,4 '-oxybis (cyclohexane-1-carboxylic acid) and 4,4' -thiobis (cyclohexane-1-carboxylic acid).

In the polyamide resin of the present embodiment, the dicarboxylic acid-derived structural unit described above may include a structural unit derived from another dicarboxylic acid other than the above-described ones in any of the 1 st preferred embodiment and the 2 nd preferred embodiment. When other dicarboxylic acid is contained, the proportion thereof is preferably 3 mol% or less, more preferably 1 mol% or less, of the total of the constituent units derived from the dicarboxylic acid.

The polyamide resin of the present embodiment may contain only 1 structural unit derived from another dicarboxylic acid, or may contain 2 or more types.

As the dicarboxylic acid constituting the dicarboxylic acid-derived structural unit that can be contained in the polyamide resin of the present embodiment, an aliphatic dicarboxylic acid can be exemplified. As the aliphatic dicarboxylic acid, known aliphatic dicarboxylic acids can be used, and examples thereof include: succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid and dodecanedicarboxylic acid.

The polyamide resin of the present embodiment may be configured to contain substantially no structural unit derived from an aliphatic dicarboxylic acid. The substantial absence means that the proportion of the structural unit derived from an aliphatic dicarboxylic acid in the structural unit derived from a dicarboxylic acid is 5 mol% or less, preferably 3 mol% or less, and more preferably 1 mol% or less.

In the polyamide resin of the present embodiment, it is preferable that more than 95 mol% (preferably 96 mol% or more, more preferably 98 mol% or more, and further 100 mol% or less) of the diamine-derived structural unit and the dicarboxylic acid-derived structural unit are structural units having a cyclic structure. By forming such a structure, a polyamide resin having a high melting point and a higher glass transition temperature can be obtained. Also, the mass reduction rate can be reduced. Further, the change in enthalpy of crystallization (Δ H) at a reduced temperature tends to be increased, and the moldability tends to be further improved. Also, the amount of air leakage can be reduced. The structural unit having a cyclic structure means that the structural unit includes a cyclic structure such as an aromatic ring or an alicyclic ring, and preferably includes either an aromatic ring or an alicyclic ring.

The polyamide resin of the present embodiment is composed of a dicarboxylic acid-derived structural unit and a diamine-derived structural unit, but may contain other sites such as a structural unit other than the dicarboxylic acid-derived structural unit and the diamine-derived structural unit, and a terminal group. As other structural units, there can be exemplified: lactams from epsilon-caprolactam, valerolactam, laurolactam, undecanolactam and the like; structural units derived from aminocarboxylic acids such as 11-aminoundecanoic acid and 12-aminododecanoic acid, but are not limited thereto. The polyamide resin of the present embodiment may contain a trace amount of components such as additives used for synthesis.

The polyamide resin of the present embodiment is preferably 70% by mass or more, more preferably 80% by mass or more, further preferably 90% by mass or more, further preferably 95% by mass or more, and further preferably 98% by mass or more of a structure unit derived from a dicarboxylic acid and a structure unit derived from a diamine.

< Property of Polyamide resin >

Next, the physical properties of the polyamide resin of the present embodiment will be described.

The polyamide resin of the present embodiment has a melting point of preferably 300 ℃ or higher, preferably 301 ℃ or higher, and more preferably 302 ℃ or higher, as measured by differential scanning calorimetry. When the lower limit value is set to the above value, the deformation and/or surface roughening of the molded article obtained by soldering the molded article using the polyamide resin of the present embodiment with low lead and/or lead-free solder can be reduced with high efficiency. The melting point is preferably 330 ℃ or lower, more preferably 321 ℃ or lower, still more preferably 316 ℃ or lower, yet more preferably 313 ℃ or lower, and yet more preferably 307 ℃ or lower. By setting the upper limit value or less, the mass reduction rate can be further reduced, and the thermal stability during molding tends to be further improved.

The melting point was measured by the method described in examples below.

The polyamide resin of the present embodiment has a glass transition temperature of preferably 100 ℃ or higher, more preferably 110 ℃ or higher, further preferably 120 ℃ or higher, further preferably 130 ℃ or higher, and further preferably 140 ℃ or higher, as measured by differential scanning calorimetry. By setting the lower limit value or more, a high elastic modulus can be more efficiently maintained even in a high-temperature environment. The glass transition temperature is preferably 200 ℃ or lower, more preferably 190 ℃ or lower, further preferably 180 ℃ or lower, further preferably 170 ℃ or lower, further preferably 160 ℃ or lower, further preferably 155 ℃ or lower, and may be 150 ℃ or lower. When the amount is equal to or less than the upper limit, the fluidity during melting tends to be high, and the moldability tends to be further improved.

The glass transition temperature was measured by the method described in the examples below.

The temperature difference (Tm-Tg) between the melting point and the glass transition temperature of the polyamide resin of the present embodiment is preferably 100 ℃ or more, more preferably 120 ℃ or more, further preferably 130 ℃ or more, further preferably 140 ℃ or more, and further preferably 150 ℃ or more. When the lower limit value is not less than the above-mentioned lower limit value, the fluidity at the time of melting is further improved, and the moldability tends to be further improved.

The lower limit of the temperature difference (Tm-Tg) between the melting point and the glass transition temperature of the polyamide resin of the present embodiment is preferably 230 ℃ or less, more preferably 200 ℃ or less, still more preferably 180 ℃ or less, yet more preferably 175 ℃ or less, and yet more preferably 172 ℃ or less. By setting the upper limit value or less, the mass reduction rate can be further reduced, and the thermal stability during molding tends to be further improved.

The polyamide resin of the present embodiment preferably has a Tm/Tg of 1.0 or more, more preferably 1.5 or more, even more preferably 1.8 or more, and even more preferably 1.9 or more. When the amount is not less than the lower limit, the fluidity during melting tends to be further improved, and the moldability tends to be further improved. The polyamide resin of the present embodiment preferably has a Tm/Tg of 3.0 or less, more preferably 2.5 or less, and still more preferably 2.3 or less. When the amount is equal to or less than the upper limit, the mass reduction rate can be further reduced, and the thermal stability during molding tends to be further improved.

The polyamide resin of the present embodiment preferably has a high change in enthalpy of cooling crystallization (Δ H), which is the area of the cooling crystallization peak evaluated by DSC measurement. Specifically, the Δ H is preferably 20J/g or more, more preferably 25J/g or more, further preferably 30J/g or more, further preferably 35J/g or more, further preferably 39J/g or more, and further preferably 40J/g or more. By setting the lower limit value or more, crystallization in the mold during injection molding is facilitated, and higher strength tends to be maintained even in a high-temperature environment. Further, the Δ H is preferably 100J/g or less, more preferably 80J/g or less, further preferably 70J/g or less, further preferably 60J/g or less, and further preferably 56J/g or less. When the upper limit value or less is set, the molding shrinkage tends to be smaller.

The change in enthalpy of crystallization at reduced temperature (. DELTA.H) was measured by the method described in the examples below.

The polyamide resin of the present embodiment preferably has a low mass decrease rate after heating at a temperature of melting point +25 ℃ for 30 minutes. Specifically, the mass reduction rate is preferably 10% or less, more preferably 9% or less, further preferably 8% or less, further preferably 6.5% or less, and further preferably 6% or less. When the amount is not more than the upper limit, the thermal stability during molding tends to be further improved, and the moldability tends to be further improved. The lower limit of the mass reduction rate is preferably 0%, but is actually 0.01% or more, and more preferably 0.1% or more.

The mass reduction rate was measured by the method described in the examples below.

The polyamide resin of the present embodiment is preferably produced by a melt polycondensation (melt polymerization) method or a pressurized salt method using a phosphorus atom-containing compound as a catalyst, and more preferably produced by the pressurized salt method. As the melt polycondensation method, the following method is preferred: the starting diamine is added dropwise to the molten starting dicarboxylic acid, and the temperature is raised under pressure to remove the water of condensation and polymerize the same. As the pressurized salt method, the following methods are preferred: in the presence of water, a salt composed of a raw material diamine and a raw material dicarboxylic acid is heated under pressure, and the added water and condensed water are removed and polymerized in a molten state.

Specific examples of the phosphorus atom-containing compound include: phosphinic acid compounds such as dimethylphosphinic acid and phenylmethylphosphinic acid; hypophosphorous acid compounds such as hypophosphorous acid, sodium hypophosphite, potassium hypophosphite, lithium hypophosphite, magnesium hypophosphite, calcium hypophosphite, and ethyl hypophosphite; phosphonic acid compounds such as phosphonic acid, sodium phosphonate, lithium phosphonate, potassium phosphonate, magnesium phosphonate, calcium phosphonate, phenylphosphonic acid, ethylphosphonic acid, sodium phenylphosphonate, potassium phenylphosphonate, lithium phenylphosphonate, diethyl phenylphosphonate, sodium ethylphosphonate, and potassium ethylphosphonate; phosphonite compounds such as phosphonous acid, sodium phosphinate, lithium phosphinate, potassium phosphinate, magnesium phosphinate, calcium phosphinate, phenylphosphonous acid, sodium phenylphosphinate, potassium phenylphosphinate, lithium phenylphosphinate, and ethyl phenylphosphonite; phosphorous acid compounds such as phosphorous acid, sodium hydrogen phosphite, sodium phosphite, lithium phosphite, potassium phosphite, magnesium phosphite, calcium phosphite, triethyl phosphite, triphenyl phosphite, and pyrophosphorous acid, etc., preferably sodium diphosphite and calcium diphosphite, and more preferably calcium hypophosphite. When calcium hypophosphite is used, the heat resistance of the obtained polyamide resin tends to be further improved.

These phosphorus atom-containing compounds may be used in 1 kind or in combination of 2 or more kinds.

The amount of the phosphorus atom-containing compound added is preferably such that the phosphorus atom concentration in the polyamide resin is 0.01 to 0.1 mass.

In the present embodiment, a polymerization rate modifier may be added in addition to the phosphorus atom-containing compound. Examples of the polymerization rate regulator include: alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal acetates and alkaline earth metal acetates, preferably alkali metal acetates.

Examples of the alkali metal atom include sodium, potassium and lithium, and sodium is preferred. Examples of the alkaline earth metal atom include calcium and magnesium.

Specific examples of the polymerization rate regulator include: lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, lithium acetate, sodium acetate, potassium acetate, rubidium acetate, cesium acetate, magnesium acetate, calcium acetate, strontium acetate, barium acetate. Among them, at least 1 selected from the group consisting of sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, sodium acetate, potassium acetate and calcium acetate is preferable, at least 1 selected from the group consisting of sodium acetate, potassium acetate and calcium acetate is more preferable, and sodium acetate is further preferable.

These polymerization rate regulators may be used alone in 1 kind or in combination of 2 or more kinds.

The addition amount of the polymerization rate modifier is preferably 0.001 to 0.5% by mass of the total amount of the diamine and the dicarboxylic acid as the raw materials.

< resin composition >

The polyamide resin of the present embodiment can be used in the form of a resin composition containing the polyamide resin of the present embodiment (hereinafter, may be referred to as "the resin composition of the present embodiment") and a molded article formed from the resin composition of the present embodiment.

The resin composition of the present embodiment may be composed of only 1 or 2 or more kinds of the polyamide resin of the present embodiment, and may contain other components.

As other components, there may be added as required: additives such as polyamide resins other than the polyamide resin of the present embodiment, thermoplastic resins other than the polyamide resin, reinforcing materials (fillers), antioxidants (particularly heat stabilizers) such as heat stabilizers and weather stabilizers, flame retardants, flame retardant aids, mold release agents, anti-dripping agents, delustering agents, ultraviolet absorbers, plasticizers, antistatic agents, anti-coloring agents, and anti-gelling agents. These additives may be 1 kind or 2 or more kinds, respectively.

Other Polyamide resins

The other polyamide resin that may be contained in the resin composition of the present embodiment may be an aliphatic polyamide resin or a semi-aromatic polyamide resin.

Examples of the aliphatic polyamide resin include: polyamide 6, polyamide 66, polyamide 46, polyamide 6/66 (copolymer comprising polyamide 6 component and polyamide 66 component), polyamide 610, polyamide 612, polyamide 410, polyamide 1010, polyamide 11, polyamide 12, polyamide 9C (polyamide composed of mixed diamine comprising 1,9-nonanediamine and 2-methyl-1,8-octanediamine with 1,4-cyclohexanedicarboxylic acid).

Examples of the semi-aromatic polyamide resin include: polyamide 4T, polyamide 6I, polyamide 6T/6I, polyamide 9T, polyamide 10T, polyamide 9N (a polyamide composed of a mixed diamine containing 1,9-nonanediamine and 2-methyl-1,8-octanediamine and 2,6-naphthalenedicarboxylic acid), and the like.

The semi-aromatic polyamide resin may be exemplified by a xylylenediamine-based polyamide resin comprising a diamine-derived structural unit and a dicarboxylic acid-derived structural unit, wherein 70 mol% or more of the diamine-derived structural unit is derived from at least one of m-xylylenediamine and p-xylylenediamine, and 70 mol% or more of the dicarboxylic acid-derived structural unit is derived from an α, ω -linear aliphatic dicarboxylic acid having 4 to 20 carbon atoms. Specifically, the following can be exemplified: MXD6, a polycondensate of m-xylylenediamine and adipic acid; MXD6I, a polycondensate of m-xylylenediamine with adipic acid and isophthalic acid; MP6 which is a polycondensate of m-xylylenediamine, p-xylylenediamine and adipic acid; MXD10, a polycondensate of m-xylylenediamine and sebacic acid; MP10, a condensation polymer of m-xylylenediamine and p-xylylenediamine with sebacic acid; a condensation polymer of p-xylylenediamine and sebacic acid, namely PXD10 and the like.

Further, as the semi-aromatic polyamide resin, there can be exemplified: a polyamide resin which is a polycondensate of at least 1 of 1,9-nonanediamine, 2-methyl-1,8-octanediamine and 1,10-decanediamine with terephthalic acid and/or naphthalenedicarboxylic acid. Particularly preferred is a polyamide resin which is a polycondensate of 1,9-nonanediamine with 2-methyl-1,8-octanediamine and naphthalenedicarboxylic acid.

When the resin composition of the present embodiment contains another polyamide resin, the content thereof is preferably 1 part by mass or more, and may be 10 parts by mass or more, and is preferably 100 parts by mass or less, more preferably 50 parts by mass or less, and still more preferably 30 parts by mass or less, with respect to 100 parts by mass of the polyamide resin of the present embodiment. The resin composition of the present embodiment may contain only 1 other polyamide resin, or may contain 2 or more polyamide resins. When 2 or more species are contained, the total amount is preferably within the above range.

< thermoplastic resin other than polyamide resin >

Examples of the thermoplastic resin other than the polyamide resin include: polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate and polybutylene naphthalate. These thermoplastic resins other than the polyamide resin may be 1 type or 2 or more types, respectively.

[ antioxidant ]

The resin composition of the present embodiment may further include an antioxidant. By including an antioxidant, a molded article having excellent heat resistance can be obtained.

As the antioxidant, a mode including an organic antioxidant can be exemplified, and more specifically, a mode including a primary antioxidant and a secondary antioxidant can be exemplified. As the antioxidant, an embodiment including an inorganic antioxidant can be exemplified. Further, both organic antioxidants and inorganic antioxidants may be contained.

The primary antioxidant functions as a so-called radical scavenger, and for example, functions to scavenge various radicals generated by active oxidation and generate hydroperoxides. Examples of the primary antioxidant include a phenol-based antioxidant (preferably, a hindered phenol-based antioxidant) and an amine-based antioxidant.

The secondary antioxidant functions as a so-called peroxide decomposer, and for example, functions to decompose generated hydroperoxide and convert the hydroperoxide into a stable alcohol compound. Examples of the secondary antioxidant include a phosphorus antioxidant and a sulfur antioxidant.

By using the primary antioxidant and the secondary antioxidant in combination, the antioxidant function acts in a chain manner, and the antioxidant effect can be embodied more efficiently. It is particularly preferable to use a combination of a phenol-based antioxidant (preferably a hindered phenol-based antioxidant) and a phosphorus-based antioxidant. When the primary antioxidant and the secondary antioxidant are used in combination, the ratio thereof is preferably 1:0.1 to 1:10 (mass ratio), more preferably 1:0.5 to 1:2, or a mixture thereof.

As the phenol-based antioxidant, specifically, a hindered phenol-based antioxidant is preferable. The hindered phenol antioxidant is, for example, a compound having a hindered phenol structure having a substituent having high steric hindrance on at least one of carbon atoms adjacent to both sides of a carbon atom to which an OH group is bonded in a phenyl group, and the substituent having high steric hindrance is usually a t-butyl group. Hindered phenol antioxidants are generally classified into symmetrical type and asymmetrical type, and symmetrical type is preferable. The symmetric type is a compound having substituents with high steric hindrance on carbon atoms adjacent to both sides of a carbon atom to which an OH group is bonded, of a phenyl group. The asymmetric type is a hindered phenol antioxidant having a substituent having a high steric hindrance on only one of carbon atoms adjacent to both sides of a carbon atom to which an OH group is bonded in a phenyl group, or a hindered phenol antioxidant having no substituent having a high steric hindrance on both carbon atoms. In particular, in the present embodiment, a hindered phenol antioxidant having 2 to 6 hindered phenol structures is preferable, and a hindered phenol antioxidant having 2 hindered phenol structures is more preferable.

In the present embodiment, a hindered phenol antioxidant having an amide bond is preferable, a symmetrical hindered phenol antioxidant having an amide bond is more preferable, a hindered phenol antioxidant having 2 to 6 amide bonds and 2 to 6 symmetrical hindered phenol structures is more preferable, a hindered phenol antioxidant having 2 to 6 di-t-butyl-4 hydroxyphenylalkylcarbonylamide groups is further preferable (the number of carbon atoms in the alkyl chain is preferably 1 to 5, more preferably 2 to 4), and N, N' -hexane-1,6 diylbis [3- (3,5-di-t-butyl-4 hydroxyphenylpropionamide ] is particularly preferable.

As a commercial product of the symmetrical hindered phenol-based antioxidant, preferred are those sold by BASF as Irganox series, and those sold by ADEKA as ADK STAB series (for example, AO-20, AO-50F, AO-60, AO-60G, AO-330), and Irganox1098 is preferred.

Hereinafter, the antioxidant preferably used in the present embodiment will be exemplified, but the present embodiment is obviously not limited to these.

Examples of the amine-based antioxidant include: n, N ' -di-2-naphthyl-P-phenylenediamine, N-diphenylethylenediamine, N-diphenylacetamidine, N-diphenylformamidine, N-phenylpiperidine, dibenzylethylenediamine, triethanolamine, phenothiazine, N ' -di-sec-butyl-P-phenylenediamine, 4,4' -tetramethyl-diaminodiphenylmethane, P, amines such as P ' -dioctyl-diphenylamine, N ' -bis (1,4-dimethyl-pentyl) -P-phenylenediamine, phenyl- α -naphthylamine, phenyl- β -naphthylamine, 4,4' -bis (α, α -dimethyl-benzyl) diphenylamine, P- (P-toluenesulfonamide) diphenylamine, N-phenyl-N ' -isopropyl-P-phenylenediamine, and the like; amines such as N-phenyl-N' - (1,3-dimethylbutyl) -p-phenylenediamine and derivatives thereof, reaction products of amines and aldehydes, reaction products of amines and ketones, and the like.

In the present embodiment, an amine-based antioxidant containing an aromatic ring is particularly preferable, and an amine-based antioxidant containing 2 or more (preferably 2 to 5) benzene rings is more preferable.

The amine antioxidant represented by the following formula (A) and the amine antioxidant represented by the following formula (B) are preferable.

Formula (A)

(in the formula (A), R ^A1 And R ^A2 Each independently is a hydrocarbyl group. )

R ^A1 And R ^A2 Preferably alkyl or aryl, more preferably R ^A1 And R ^A2 At least one of which is an aryl group. The alkyl group and the aryl group may have a substituent. Aryl groups may be exemplified by phenyl and naphthyl.

Formula (B)

R ^B2 -NH-R ^B1

(in the formula (B), R ^B1 And R ^B2 Each independently is a hydrocarbon group containing an aromatic ring. )

R ^B1 And R ^B2 The hydrocarbon group is preferably a hydrocarbon group having 2 or more aromatic rings, more preferably a hydrocarbon group having 2 aromatic rings, still more preferably a hydrocarbon group having 2 benzene rings, and yet more preferably a hydrocarbon group in which 2 benzene rings are linked by an alkylene group having 1 to 4 carbon atoms.

The molecular weight of the amine antioxidant represented by formula (a) and the amine antioxidant represented by formula (B) is preferably 200 to 1200, more preferably 300 to 600.

It is considered that the antioxidant represented by the formula (a) has an amine as an active site at 2 positions, and the effect of the present embodiment can be effectively exhibited. Further, other compounds may be copolymerized within a range not departing from the gist of the present embodiment.

Examples of the phosphorus-based antioxidant include phosphites and phosphates, and phosphites are more preferred.

Specific examples of the phosphorus-based antioxidant include: monosodium phosphate, disodium phosphate, trisodium phosphate, sodium phosphite, calcium phosphite, magnesium phosphite, manganese phosphite, pentaerythritol-type phosphite compounds, trioctyl phosphite, trilauryl phosphite, octyldiphenyl phosphite, triisodecyl phosphite, phenyldiisodecyl phosphite, phenylditridecyl phosphite, and the like diphenylisooctyl phosphite, diphenylisodecyl phosphite, diphenyl (tridecyl) phosphite, triphenyl phosphite, trioctadecyl phosphite, tridecyl phosphite, tris (nonylphenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, diphenylisooctyl phosphite, diphenylisodecyl phosphite, diphenyltridecyl phosphite, triphenylphosphite, tris (octadecyl) phosphite, tridecyl phosphite, tris (nonylphenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, diphenylisooctyl phosphite, diphenyltridecyl phosphite, triphenylphosphite, and triphenylphosphite tris (2,4-di-tert-butyl-5-methylphenyl) phosphite, tris (butoxyethyl) phosphite, 4,4 '-butylidene-bis (3-methyl-6-tert-butylphenyl-tetrakis (tridecyl)) diphosphite, tetrakis (C12-C15 mixed alkyl) -4,4' -isopropylidenediphosphite, 4,4 '-isopropylidene-bis (2-tert-butylphenyl) -bis (nonylphenyl) phosphite, tris (biphenyl) phosphite, tetrakis (tridecyl) -1,1,3-tris (2-methyl-5-tert-butyl-4-hydroxyphenyl) butane diphosphite, tetrakis (tridecyl) -4,4' -butylidene-bis (3-methyl-6-tert-butylphenyl) diphosphite, tris (tridecyl) -3534, tetrakis (C1-C15 mixed alkyl) -4,4' -isopropylidenediphenyl phosphite, tris (mono-and di-mixed nonylphenyl) phosphite, 4,4' -isopropylidenebis (2-tert-butylphenyl) -bis (nonylphenyl) phosphite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, tris (3,5-di-tert-butyl-4-hydroxyphenyl) phosphite, hydro-4,4 ' -isopropylidenediphenyl phosphite, bis (octylphenyl) -bis (4,4 ' -butylidenebis (3-methyl-6-tert-butylphenyl)). 1,6-hexanol diphosphite hexakis (tridecyl) -1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) diphosphite, tris (4,4 ' -isopropylidenebis (2-t-butylphenyl)) phosphite, tris (1,3-stearoyloxyisopropyl) phosphite, 2,2-methylenebis (4,6-di-t-butylphenyl) octylphosphite, 2,2-methylenebis (3-methyl-4,6-di-t-butylphenyl) -2-ethylhexyl phosphite, tetrakis (2,4-di-t-butyl-5-methylphenyl) -4,4' -biphenylenediphosphite, tetrakis (2,4-di-t-butylphenyl) -4,4' -biphenylenediphosphite, 6- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propoxy ] -2,4,8,10-tetra-tert-butyldibenzo [ d, f ] [1,3,2] -dioxaphosphepin, and the like.

In the present embodiment, a phosphorus antioxidant represented by the following formula (P) is particularly preferable.

Formula (P)

(in the formula (P), R ^P1 And R ^P2 Each independently is a hydrocarbyl group. )

R ^P1 And R ^P2 Preferably aryl, more preferably phenyl. The aryl group may have a substituent. As the substituent, a hydrocarbon group, preferably an alkyl group, may be listed. The substituent may further have a substituent such as a hydrocarbon group.

The compound represented by the formula (P) preferably has a molecular weight of 400 to 1200, more preferably 500 to 800.

Examples of the sulfur-based antioxidant include dilauryl thiodipropionate, distearyl thiodipropionate, dimyristyl thiodipropionate, lauryl stearyl thiodipropionate, pentaerythritol tetrakis (3-dodecylthiopropionate) and pentaerythritol tetrakis (3-laurylthiopropionate), and commercially available products (all trade names) such as DSTP "ヨシトミ", DLTP "ヨシトミ", DLTOIB and DMTP "ヨシトミ" (manufactured by API Corporation, supra), seenox 412S (manufactured by SHIPRO chemical Co., ltd.), cyanox 1212 (manufactured by Cyanamid Co., ltd.) and SUMILIZER TP-D (manufactured by Sumitomo chemical Co., ltd.) can be used.

Examples of the inorganic antioxidant include a copper compound and a halogenated base.

Examples of the copper compound used in the present embodiment include copper halides (e.g., copper iodide, copper bromide, and copper chloride) and copper acetate, and the copper compound is preferably selected from the group consisting of cuprous iodide, cupric iodide, cuprous bromide, cupric bromide, cuprous acetate, and cupric acetate, cuprous chloride, and cupric chloride, and more preferably selected from the group consisting of cupric iodide, cupric acetate, and cuprous chloride.

The halogenated base used in the present embodiment is a halide of an alkali metal. As the alkali metal, potassium and sodium are preferable, and potassium is more preferable. The halogen atom is preferably iodine, bromine or chlorine, and more preferably iodine. Specific examples of the alkali halide used in the present embodiment include potassium iodide, potassium bromide, potassium chloride, and sodium chloride.

In addition, the copper compound is preferably used in combination with a halogenated base. When combining a copper compound with a halogenated base, it is preferably a copper compound: halogenated base 1:3 to 1:15 The mixture (mass ratio) is more preferably 1:4 to 1:8 in the presence of a solvent.

In the case of combining a copper compound with a halogenated base, reference is also made to the descriptions in paragraphs 0046 to 0048 of Japanese patent application laid-open No. 2013-513681, which are incorporated herein by reference.

In addition, as the antioxidant other than the above, a mixture of a copper complex and a halogen-containing phosphate ester may be used, or a mixture of the copper complex and the halogen-containing phosphate ester and the above antioxidant may be used, and the antioxidants described in paragraphs 0025 to 0039 of Japanese patent application laid-open No. 2019-532168 may be used, and these contents are incorporated in the present specification.

Further, as the antioxidant other than the above, a polyhydric alcohol may be used, or a mixture of the polyhydric alcohol and the above antioxidant may be used, and the antioxidants described in paragraphs 0039 to 0045 of japanese patent publication No. 2013-538927 and paragraphs 0083 to 0085 of japanese patent publication No. 2014-525506 may be used, and these contents are incorporated in the present specification.

Further, as the antioxidant other than the above, a metal cyanide salt may be used, a mixture of the metal cyanide salt and the above antioxidant may be used, and the antioxidant described in paragraphs 0018 to 0019 of WO2018/101163 publication may be used, which are incorporated in the present specification.

In addition to the above, as the antioxidant, antioxidants described in paragraphs 0025 to 0030 of japanese patent 6466632, antioxidants described in paragraphs 0017 to 0020 of japanese patent laid-open No. 2016-074804, antioxidants described in paragraphs 0044 to 0048 of japanese patent laid-open No. 2021-038370, antioxidants described in paragraphs 0043 to 0056 of japanese patent laid-open No. 2012-179911, antioxidants described in paragraphs 0045 to 0056 of japanese patent laid-open No. 2020-033539, and antioxidants described in paragraphs 0030 to 0038 of international publication No. 2010/143638 can be used, and these contents are incorporated in the present specification.

When the resin composition of the present embodiment contains the antioxidant, the content thereof is preferably 0.01 part by mass or more, more preferably 0.05 part by mass or more, further preferably 0.1 part by mass or more, further preferably 0.2 part by mass or more, and further preferably 0.4 part by mass or more, based on 100 parts by mass of the polyamide resin. When the lower limit value is not less than the above-mentioned lower limit value, the retention of the weight average molecular weight after heat aging tends to be improved, and the retention of the mechanical strength tends to be improved. The content is preferably 10.0 parts by mass or less, more preferably 5.0 parts by mass or less, further preferably 3.0 parts by mass or less, further preferably 2.0 parts by mass or less, and further preferably 1.5 parts by mass or less, per 100 parts by mass of the polyamide resin. By setting the upper limit value or less, blow-by gas during molding is reduced, so that contamination of the mold is reduced, and continuous productivity tends to be improved.

The resin composition of the present embodiment may contain only 1 kind of antioxidant, or may contain 2 or more kinds. When 2 or more species are contained, the total amount is preferably within the above range.

Flame retardant

The resin composition of the present embodiment may contain a flame retardant. By including a flame retardant, flame retardancy can be improved.

Examples of the flame retardant include a phosphorus flame retardant, a halogen flame retardant, and an organic metal salt flame retardant, preferably a phosphorus flame retardant and a halogen flame retardant, and more preferably a phosphorus flame retardant.

Examples of the phosphorus-based flame retardant include: ethyl phosphinate metal salt, diethyl phosphinate metal salt, melamine polyphosphate, condensed phosphate ester, phosphazene compound, and the like, and among them, condensed phosphate ester or phosphazene is preferable. In addition, a thermoplastic resin having excellent compatibility with the phosphorus flame retardant may be blended in order to suppress generation of gas or mold deposit during molding and bleeding of the flame retardant. As such a thermoplastic resin, a polyphenylene ether resin, a polycarbonate resin, and a styrene resin are preferable.

The condensed phosphoric ester is preferably a compound represented by the following formula (FP 1).

Formula (FP 1)

(in the formula (FP 1), R ^f1 、R ^f2 、R ^f3 And R ^f4 Each independently represents a hydrogen atom or an organic group. But does not include R ^f1 、R ^f2 、R ^f3 And R ^f4 All are hydrogen atoms. X represents a 2-valent organic group, p is 0 or 1,q represents an integer of 1 or more, and r represents an integer of 0 or 1 or more. )

In the formula (FP 1), examples of the organic group include an alkyl group, a cycloalkyl group and an aryl group. Further, the compound may have a substituent such as an alkyl group, an alkoxy group, an alkylthio group, an aryl group, an aryloxy group, an arylthio group, a halogen atom, or a halogenated aryl group. Further, these substituents may be combined, or these substituents may be combined by bonding through an oxygen atom, a sulfur atom, a nitrogen atom or the like. The 2-valent organic group is a group having a valence of 2 or more obtained by removing 1 carbon atom from the above organic group. Examples thereof include alkylene groups, phenylene groups, substituted phenylene groups, polynuclear phenylene groups derived from bisphenols, and the like. The formula weight of each of these groups is preferably 15 to 300, more preferably 15 to 200, and still more preferably 15 to 100.

Specific examples of the condensed phosphoric ester represented by the formula (FP 1) include: trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, triphenyl phosphate, tricresyl phosphate, octyl diphenylphosphate, diisopropylphenyl phosphate, tris (chloroethyl) phosphate, tris (dichloropropyl) phosphate, tris (chloropropyl) phosphate, bis (2,3-dibromopropyl) phosphate, bis (2,3-dibromopropyl) -2,3-dichlorophosphate, bis (chloropropyl) monooctyl phosphate, tetraphenylbisphenol A diphosphate, tetramethylphenylbhenol A diphosphate, tetraxylyl bisphenol A diphosphate, tetraphenylhydroquinone diphosphate, tetramethylphenylhydroquinone diphosphate, tetraxylyl hydroquinone diphosphate, and the like.

Further, commercially available condensed phosphates are, for example, "CR733S" (resorcinol bis (diphenyl phosphate)), "CR741" (bisphenol A bis (diphenyl phosphate)), "PX-200" (resorcinol bis [ dixylyl phosphate ]); it is easily available from Asahi Denka Kogyo Co., ltd under the trade name "ADK STAB FP-700" (2,2-bis (p-hydroxyphenyl) propane/trichlorooxyphosphine polycondensate (phenol condensate having a polymerization degree of 1 to 3)).

The phosphazene compound is an organic compound having a bond of-P = N-in the molecule, and is preferably at least 1 compound selected from the group consisting of a cyclic phosphazene compound represented by formula (FP 2), a chain phosphazene compound represented by formula (FP 3), and a crosslinked phosphazene compound in which at least 1 phosphazene compound selected from the group consisting of formula (FP 2) and formula (FP 3) is crosslinked by a crosslinking group.

Formula (FP 2)

(in the formula (FP 2), a is an integer of 3 to 25, R ^f5 And R ^f6 Which may be the same or different, represent alkyl, cycloalkyl, alkenyl, alkynyl, allyloxy, amino, hydroxy, aryl or alkylaryl. )

Formula (FP 3)

(in the formula (FP 3), b is an integer of 3 to 10000, R ^f7 And R ^f8 Identical or different, represents alkyl, cycloalkyl, alkenyl, alkynyl, aryloxy, amino, hydroxyl, aryl or alkylaryl. )

R ^f9 Represents a group selected from-N = P (OR) ^f7 ) ₃ Radical, -N = P (OR) ^f8 ) ₃ Radical, -N = P (O) OR ^f7 Radical, -N = P (O) OR ^f8 At least 1 of the radicals, R ^f10 Represents a group selected from-P (OR) ^f7 ) ₄ Radical, -P (OR) ^f8 ) ₄ Radical, -P (O) (OR) ^f7 ) ₂ Radical, -P (O) (OR) ^f8 ) ₂ At least 1 of the groups.

In the formulae (FP 2) and (FP 3), examples of the alkyl group include: methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, pentyl, hexyl, octyl, decyl, dodecyl and the like, preferably an alkyl group having 1 to 6 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, pentyl, hexyl and the like, and particularly preferably an alkyl group having 1 to 4 carbon atoms such as methyl, ethyl, propyl and the like.

Examples of the cycloalkyl group include: cycloalkyl groups having 5 to 14 carbon atoms such as cyclopentyl and cyclohexyl, and preferably cycloalkyl groups having 5 to 8 carbon atoms.

Examples of the alkenyl group include: alkenyl groups having 2 to 8 carbon atoms such as vinyl and allyl. Examples of cycloalkenyl groups include: a cycloalkenyl group having 5 to 12 carbon atoms such as a cyclopentyl group and a cyclohexyl group.

Examples of alkynyl groups include: an alkynyl group having 2 to 8 carbon atoms such as an ethynyl group and propynyl group; and alkynyl groups having an aryl group such as ethynylphenyl as a substituent.

Examples of the aryl group include: aryl groups having 6 to 20 carbon atoms such as phenyl, methylbenzene (i.e., tolyl) group, dimethylbenzene (i.e., xylyl) group, trimethylphenyl group, naphthyl group and the like, among which aryl groups having 6 to 10 carbon atoms are preferable, and phenyl group is particularly preferable.

Examples of the alkylaryl group include: aralkyl groups having 6 to 20 carbon atoms such as benzyl, phenethyl and phenylpropyl, among them, aralkyl groups having 7 to 10 carbon atoms are preferable, and benzyl is particularly preferable.

Wherein R in the formula (FP 2) ^f5 And R ^f6 R in the general formula (FP 3) ^f7 And R ^f8 Preferably, the aryl group and the arylalkyl group are used, more preferably, the aryl group is used, and still more preferably, the phenyl group is used. By using such an aromatic phosphazene, the thermal stability of the resin composition obtained can be improved efficiently.

Examples of the cyclic and/or chain phosphazene compound represented by the formula (FP 2) and the formula (FP 3) include: (poly) tolyloxyphosphazenes such as phenoxyphosphazene, o-tolyloxyphosphazene, m-tolyloxyphosphazene and p-tolyloxyphosphazene; (poly) xylyloxy phosphazenes such as o, m-xylyloxy phosphazene, o, p-xylyloxy phosphazene, and m, p-xylyloxy phosphazene; (poly) phenoxytolyloxyphosphazenes such as o-, m-, p-trimethylphenyloxyphosphazene, phenoxy o-tolyloxyphosphazene, phenoxy m-tolyloxyphosphazene and phenoxy p-tolyloxyphosphazene; (poly) phenoxy tolyloxy ditolyloxyphosphazenes such as phenoxy o-, m-, p-, and m-, p-ditolyloxyphosphazenes; phenoxy o-, m-, p-trimethylphenyloxyphosphazene and the like, and preferably cyclic and/or chain phenoxyphosphazene and the like.

As the cyclic phosphazene compound represented by the formula (FP 2), R is particularly preferable ^f5 And R ^f6 A cyclic phenoxyphosphazene which is a phenyl group. Examples of the cyclic phenoxyphosphazene compound include: the compound of phenoxy cyclotriphosphazene, octaphenoxy cyclotetraphosphazene, decaphenoxy cyclopentaphosphazene and the like is obtained by the following method: ammonium chloride and phosphorus pentachloride are reacted at 120-130 deg.c to obtain cyclic and straight chain phosphonitrile chloride mixture, and the cyclic phosphonitrile chloride such as hexachlorocyclotriphosphazene, octachlorocyclotetraphosphazene, decachlorocyclopentaphosphazene, etc. is taken out from the mixture and substituted with phenoxy radical to obtain the product. The cyclic phenoxyphosphazene compound is preferably a compound in which a is an integer of 3 to 8 in the formula (FP 2), and may be a mixture of compounds having different a.

The average value of a is preferably 3 to 5, more preferably 3 to 4. Among them, a mixture of compounds in which a =3 is 50% by mass or more, a =4 is 10 to 40% by mass, and a =5 is 30% by mass or less in total is preferable.

As the chain phosphazene compound represented by the formula (FP 3), R is particularly preferable ^f7 And R ^f8 A linear phenoxyphosphazene which is a phenyl group. Examples of such chain phenoxyphosphazene compounds include: the hexachlorocyclotriphosphazene obtained by the above method is ring-opened polymerized at a temperature of 220 to 250 ℃ and the linear dichlorphosphazene having a degree of polymerization of 3 to 10000 is substituted with phenoxy group. The linear phenoxyphosphazene compound b in the formula (FP 3) is preferably 3 to 1000, more preferably 3 to 100, and further preferably 3 to 25.

Examples of the crosslinked phosphazene compound include: a compound having a crosslinked structure of 4,4' -sulfonyldiphenylene (i.e., bisphenol S residue), a compound having a crosslinked structure of 2,2- (4,4 ' -diphenylene) isopropylidene, a compound having a crosslinked structure of 4,4' -oxydiphenylene, a compound having a crosslinked structure of 4,4' -thiodiphenylene, and the like, a compound having a crosslinked structure of 4,4' -diphenylene, and the like.

In addition, as the cross-linked phosphazene compound, from the viewpoint of flame retardancy, R in the formula (FP 3) is preferable ^f7 、R ^f8 Cyclic phenoxyphosphazene compounds which are phenyl groups utilizing the aboveA crosslinked phenoxyphosphazene compound obtained by crosslinking a crosslinking group, or R in the formula (FP 3) ^f7 、R ^f8 The crosslinked phenoxyphosphazene compound in which a chain phenoxyphosphazene compound which is a phenyl group is crosslinked by the crosslinking group is more preferable to be a crosslinked phenoxyphosphazene compound in which a cyclic phenoxyphosphazene compound is crosslinked by the crosslinking group.

The content of phenylene in the crosslinked phenoxyphosphazene compound is usually 50 to 99.9%, preferably 70 to 90%, based on the total number of phenyl groups and phenylene groups in the cyclic phosphazene compound represented by formula (FP 2) and/or the chain phenoxyphosphazene compound represented by formula (FP 3). The crosslinked phenoxyphosphazene compound is particularly preferably a compound having no free hydroxyl group in the molecule.

In the present embodiment, the phosphazene compound is preferably at least 1 selected from the group consisting of a cyclic phenoxyphosphazene compound represented by formula (FP 2) and a crosslinked phenoxyphosphazene compound in which the cyclic phenoxyphosphazene compound represented by formula (FP 2) is crosslinked by a crosslinking group, from the viewpoint of flame retardancy and mechanical properties of the resin composition.

As a commercially available product of the phosphazene compound, FP-110 manufactured by pharmaceutical company is exemplified.

The halogen-based flame retardant is preferably a bromine-based flame retardant or a chlorine-based flame retardant, and more preferably a bromine-based flame retardant.

Examples of the bromine-based flame retardant include: hexabromocyclododecane, decabromodiphenyl ether, octabromodiphenyl ether, tetrabromobisphenol a, bis (tribromophenoxy) ethane, bis (pentabromophenoxy) ethane, tetrabromobisphenol a epoxy resin, tetrabromobisphenol a carbonate, ethylene (bistetrabromophthalic acid) imide, ethylene bistentabromobenzene, tris (tribromophenoxy) triazine, bis (dibromopropyl) tetrabromobisphenol a, bis (dibromopropyl) tetrabromobisphenol S, brominated polyphenylene ethers (including poly (di) bromophenyl ether, etc.), brominated polystyrenes (polydibromostyrene, polytribromostyrene, crosslinked brominated polystyrenes), brominated polycarbonates, and the like.

The organic metal salt-based flame retardant is preferably an organic alkali metal salt compound or an organic alkaline earth metal salt compound (hereinafter, the alkali metal and the alkaline earth metal are referred to as "alkali (earth) metal"). Further, as the organic metal salt-based flame retardant, a sulfonic acid metal salt, a carboxylic acid metal salt, a boric acid metal salt, a phosphoric acid metal salt and the like are exemplified, and from the viewpoint of thermal stability when added to the aromatic polycarbonate resin, a sulfonic acid metal salt is preferable, and a perfluoroalkane sulfonic acid metal salt is particularly preferable.

Examples of the sulfonic acid metal salt include: lithium sulfonate (Li) salt, sodium sulfonate (Na) salt, potassium sulfonate (K) salt, rubidium sulfonate (Rb) salt, cesium sulfonate (Cs) salt, magnesium sulfonate (Mg) salt, calcium sulfonate (Ca) salt, strontium sulfonate (Sr) salt, barium sulfonate (Ba) salt, etc., among which sodium sulfonate (Na) salt and potassium sulfonate (K) salt are particularly preferable.

Examples of such sulfonic acid metal salts include: aromatic sulfonic acid base (earth) metal salt compounds such as dipotassium diphenylsulfone-3,3' -disulfonate, potassium diphenylsulfone-3-sulfonate, sodium benzenesulfonate, (poly) sodium styrenesulfonate, sodium p-toluenesulfonate, (branched) sodium dodecylbenzenesulfonate, sodium trichlorobenzenesulfonate, potassium benzenesulfonate, potassium styrenesulfonate, potassium (poly) styrenesulfonate, potassium p-toluenesulfonate, (branched) potassium dodecylbenzenesulfonate, potassium trichlorobenzenesulfonate, cesium benzenesulfonate, (poly) cesium styrenesulfonate, cesium p-toluenesulfonate, (branched) cesium dodecylbenzenesulfonate, and cesium trichlorobenzenesulfonate; a metal salt of a perfluoroalkane sulfonic acid such as an alkali metal salt of a perfluoroalkane sulfonic acid (preferably, the number of carbon atoms in the paraffin is 2 to 6). Among them, diphenylsulfone-3,3' -dipotassium disulfonate, potassium diphenylsulfone-3-sulfonate, sodium p-toluenesulfonate, potassium p-toluenesulfonate, and potassium perfluorobutylsulfonate are preferable because they are excellent in balance between transparency and flame retardancy, and metal salts of perfluoroalkane sulfonic acid such as potassium perfluorobutylsulfonate are particularly preferable.

When the resin composition of the present embodiment contains a flame retardant, the content thereof is preferably 0.01 part by mass or more, more preferably 1 part by mass or more, further preferably 5 parts by mass or more, particularly preferably 6 parts by mass or more, and further preferably 7 parts by mass or more, relative to 100 parts by mass of the polyamide resin. The content of the flame retardant is preferably 40 parts by mass or less, more preferably 40 parts by mass or less, further preferably 50 parts by mass or less, particularly preferably 35 parts by mass or less, and further preferably 30 parts by mass or less, based on 100 parts by mass of the polyamide resin.

The resin composition of the present embodiment may contain only 1 kind of flame retardant, or may contain 2 or more kinds. When 2 or more species are contained, the total amount is preferably within the above range.

Flame-retardant auxiliary agent

The resin composition of the present embodiment may further contain a flame retardant aid.

Examples of the flame retardant auxiliary include: antimony compounds, zinc stannate, copper oxides, magnesium oxides, zinc oxides, molybdenum oxides, zirconium oxides, tin oxides, iron oxides, titanium oxides, aluminum oxides, zinc borate, and the like, and preferably antimony compounds and zinc stannate. In particular, zinc stannate is preferable when a phosphorus flame retardant is used, and an antimony compound is preferable when a halogen flame retardant is used.

As zinc stannate, zinc stannate trioxide (ZnSnO) is preferred ₃ ) And zinc tin (ZnSn (OH) ₆ ) At least any 1 of them is used as zinc stannate.

The antimony-based compound is a compound containing antimony and contributes to flame retardancy. Specifically, antimony trioxide (Sb) may be mentioned ₂ O ₃ ) Antimony tetraoxide, antimony pentaoxide (Sb) ₂ O ₅ ) Antimony oxide, etc.; sodium antimonate; antimony phosphate, and the like. Among them, antimony oxide is preferable because it is excellent in moist heat resistance. Further, antimony trioxide is preferably used.

As for the content of the flame-retardant auxiliary, it is preferable to use a flame retardant: the flame-retardant auxiliary agent is 1:0.05 to 2.0 (mass ratio), and more preferably 1:0.2 to 1.0.

The resin composition of the present embodiment may contain only 1 kind of flame retardant auxiliary, or may contain 2 or more kinds. When 2 or more species are contained, the total amount is preferably within the above range.

Reinforcing material (filler) >

The resin composition of the present embodiment may contain a reinforcing material, and the reinforcing material is preferably contained in the resin composition at a ratio of 5.0 to 60.0 mass%.

The reinforcing material usable in the present embodiment is not particularly limited in kind and the like, and may be any of fibers, fillers, flakes, beads and the like, and fibers are preferable.

When the reinforcing material is a fiber, the reinforcing material may be a short fiber or a long fiber.

When the reinforcing material is short fibers, fillers, beads, or the like, the resin composition of the present embodiment may be exemplified by pellets, a powder of the pellets, a film molded from the pellets, and the like.

When the reinforcing material is a long fiber, examples of the reinforcing material include a long fiber for so-called UD (Uni-Directional), a sheet-like long fiber such as a woven fabric and a knitted fabric, and the like. When these long fibers are used, the components other than the reinforcing material of the resin composition of the present embodiment may be impregnated in the reinforcing material, which is the aforementioned long fibers in a sheet form, to prepare a resin composition (for example, a prepreg) in a sheet form.

Examples of the raw materials for the reinforcing material include: inorganic substances such as glass, carbon (carbon fiber and the like), alumina, boron, ceramics, metals (steel and the like), asbestos, clay, zeolite, potassium titanate, barium sulfate, titanium oxide, silicon oxide, aluminum oxide, magnesium hydroxide and the like; and organic substances such as plants (including kenaf (kenaf), bamboo, etc.), aramid, polyoxymethylene, aromatic polyamide, polyparaphenylene benzobisoxazole, ultra high molecular weight polyethylene, etc., and preferably glass.

The resin composition of the present embodiment preferably contains glass fibers as a reinforcing material.

The glass fiber is selected from glass components such as A glass, C glass, E glass, R glass, D glass, M glass, S glass, etc., and E glass (alkali-free glass) is particularly preferable.

The glass fiber is a fibrous material having a cross-sectional shape of a perfect circle or a polygonal shape obtained by cutting at right angles in the longitudinal direction. The number average fiber diameter of the single fibers of the glass fiber is usually 1 to 25 μm, preferably 5 to 17 μm. When the number average fiber diameter is 1 μm or more, the molding processability of the resin composition tends to be further improved. When the number average fiber diameter is 25 μm or less, the appearance of the obtained molded article tends to be improved and the reinforcing effect tends to be improved. The glass fiber may be a single fiber or a fiber obtained by twisting a plurality of single fibers.

The morphology of the glass fibers may be: the chopped glass fiber is preferably a chopped glass fiber obtained by continuously winding a single fiber or a plurality of single fibers, a chopped strand having a length of 1 to 10mm (i.e., a glass fiber having a number average fiber length of 1 to 10 mm), a milled fiber having a length of 10 to 500 μm (i.e., a glass fiber having a number average fiber length of 10 to 500 μm), or the like, and preferably a chopped strand having a length of 1 to 10 mm. The glass fibers may be used in combination with glass fibers of different forms.

The glass fiber preferably has a deformed cross-sectional shape. The irregular cross-sectional shape is such that the aspect ratio expressed by the major axis/minor axis ratio of the cross-section perpendicular to the longitudinal direction of the fiber is, for example, 1.5 to 10, preferably 2.5 to 10, more preferably 2.5 to 8, and particularly preferably 2.5 to 5.

The glass fiber may be a glass fiber surface-treated with a silane compound, an epoxy compound, a urethane compound, or the like, or a glass fiber oxidized, for example, in order to improve the affinity with the resin component, as long as the properties of the resin composition of the present embodiment are not significantly impaired.

The reinforcing material used in the present embodiment may be a reinforcing material having electrical conductivity. Specifically, examples include metals, metal oxides, conductive carbon compounds, and conductive polymers, and conductive carbon compounds are preferable.

Examples of the metal include copper, nickel, silver, and stainless steel, and a metal filler, stainless steel fiber, and a magnetic filler are preferable. Examples of the metal oxide include alumina and zinc oxide, and alumina fiber and zinc oxide nanotubes are preferable. The conductive carbon compound is preferably carbon black, ketjen carbon, graphene, graphite, fullerene, carbon nanocoil, carbon nanotube, or carbon fiber, and more preferably carbon nanotube.

Further, fibers coated with a metal, a metal oxide, or a conductive carbon compound are also preferable. For example, potassium titanate whiskers coated with carbon, metal-coated fibers, and the like can be exemplified.

Further, as the reinforcing material, mention may be made of paragraphs 0033 to 0041 of japanese patent application laid-open No. 2021-031633, the contents of which are incorporated in the present specification.

When the resin composition of the present embodiment contains a reinforcing material (preferably, glass fiber), the content thereof is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, further preferably 30 parts by mass or more, and further preferably 40 parts by mass or more, per 100 parts by mass of the polyamide resin. When the lower limit value is not less than the above-mentioned lower limit value, the mechanical strength of the obtained molded article tends to be further increased. The content of the reinforcing material (preferably, glass fiber) is preferably 100 parts by mass or less, more preferably 90 parts by mass or less, still more preferably 85 parts by mass or less, yet more preferably 80 parts by mass or less, and yet more preferably 75 parts by mass or less, based on 100 parts by mass of the polyamide resin. When the amount is equal to or less than the upper limit, the molded body appearance tends to be improved and the fluidity of the resin composition tends to be further improved.

The resin composition of the present embodiment may contain only 1 kind of reinforcing material (preferably, glass fiber), or may contain 2 or more kinds. When 2 or more species are contained, the total amount is preferably within the above range.

Nucleating agent

The resin composition of the present embodiment may contain a nucleating agent. By including a nucleating agent, the crystallization speed can be increased.

The nucleating agent is not particularly limited as long as it is a nucleus that is not melted at the time of melt processing and can be a crystal during cooling, and may be an organic nucleating agent or an inorganic nucleating agent, and preferably an inorganic nucleating agent.

Examples of the inorganic nucleating agent include: graphite, molybdenum disulfide, barium sulfate, talc, calcium carbonate, sodium phosphate, mica, and kaolin, more preferably at least 1 selected from talc and calcium carbonate, and further preferably talc.

The organic nucleating agent is not particularly limited, and a known nucleating agent can be used, and for example, the nucleating agent is preferably at least 1 selected from dibenzylidene sorbitol-based nucleating agents, nonanol-based nucleating agents, phosphate salt-based nucleating agents, rosin-based nucleating agents, benzoate metal salt-based nucleating agents, and the like.

The lower limit of the number average particle diameter of the nucleating agent is preferably 0.1 μm or more. The upper limit of the number average particle diameter of the nucleating agent is preferably 40 μm or less, more preferably 30 μm or less, still more preferably 28 μm or less, yet more preferably 15 μm or less, and yet more preferably 10 μm or less. When the number average particle diameter is 40 μm or less, the amount of the nucleating agent forming the core is increased as compared with the amount of the nucleating agent blended, and therefore, the crystal structure tends to be more stabilized.

The content of the nucleating agent in the resin composition of the present embodiment is more than 0.01 part by mass, preferably 0.05 part by mass or more, more preferably 0.1 part by mass or more, further preferably 0.3 part by mass or more, and further preferably 0.7 part by mass or more, relative to 100 parts by mass of the polyamide resin. By setting the lower limit value or more, the crystalline state of the resin composition can be more sufficiently stabilized. The content of the nucleating agent in the resin composition of the present embodiment is 10 parts by mass or less, preferably 5 parts by mass or less, more preferably 3 parts by mass or less, and may be 2 parts by mass or less, based on 100 parts by mass of the polyamide resin.

When the resin composition of the present embodiment contains a nucleating agent, only 1 kind of nucleating agent may be contained, or 2 or more kinds may be contained. When 2 or more species are contained, the total amount is preferably within the above range.

Mold release agent

The resin composition of the present embodiment may contain a release agent.

Examples of the release agent include: aliphatic carboxylic acids, salts of aliphatic carboxylic acids, esters of aliphatic carboxylic acids with alcohols, aliphatic hydrocarbon compounds having a number average molecular weight of 200 to 15000, silicone-based silicone oils, ketone waxes, stearamides and the like, and are preferably aliphatic carboxylic acids, salts of aliphatic carboxylic acids, esters of aliphatic carboxylic acids with alcohols, and more preferably salts of aliphatic carboxylic acids.

Details of the release agent can be found in paragraphs 0055 to 0061 of Japanese patent application laid-open No. 2018-095706, which are incorporated herein by reference.

When the resin composition of the present embodiment contains a release agent, the content thereof is preferably 0.05 to 3% by mass, more preferably 0.1 to 0.8% by mass, and still more preferably 0.2 to 0.6% by mass in the resin composition.

The resin composition of the present embodiment may contain only 1 kind of release agent, or may contain 2 or more kinds. When 2 or more species are contained, the total amount is preferably within the above range.

< method for producing resin composition >

The method for producing the resin composition of the present embodiment is not particularly limited, and a known method for producing a thermoplastic resin composition can be widely used. Specifically, the resin composition can be produced by mixing the components in advance with various mixers such as a tumbler and a henschel mixer, and then melt-kneading the mixture with a banbury mixer, a roll, a Brabender, a single-screw extruder, a twin-screw extruder, a kneader, or the like.

For example, the resin composition of the present embodiment may be produced by supplying the components to an extruder using a feeder without premixing the components or by premixing only a part of the components and melt-kneading the components. Further, for example, the resin composition of the present embodiment may be produced by mixing a part of the components in advance, supplying the mixture to an extruder, and melt-kneading the mixture to obtain a master batch, mixing the master batch again with the remaining components, and melt-kneading the mixture.

< shaped article >

The molded article is formed from the polyamide resin of the present embodiment or the resin composition of the present embodiment.

The method for molding the molded article is not particularly limited, and conventionally known molding methods can be used, and examples thereof include: injection molding, injection compression molding, extrusion molding, profile extrusion, transfer molding, blow molding, gas-assisted blow molding, extrusion blow molding, IMC (In-mold coating) molding, rotational molding, multilayer molding, two-color molding, insert molding, sandwich molding, foam molding, press molding, drawing, vacuum molding, and the like.

Examples of the molded article formed from the composition of the present embodiment include: injection molded articles, thin-walled molded articles, hollow molded articles, films (including plates and sheets), cylinders (hoses, tubes, etc.), rings, circles, ovals, gears, polygons, profiles, hollow articles, frames, boxes, plate-shaped extrusion molded articles, fibers, and the like.

The polyamide resin or the polyamide resin composition of the present embodiment is also preferably used as the following material.

Can exemplify: a prepreg obtained by impregnating the reinforcing material (in particular, reinforcing fibers, preferably carbon fibers or glass fibers) with the polyamide resin or polyamide resin composition of the present embodiment; a mixed yarn, tape or twisted rope containing, as fiber components, a continuous thermoplastic resin fiber comprising the polyamide resin or polyamide resin composition of the present embodiment and a continuous reinforcing fiber; a woven or knitted fabric using a continuous thermoplastic resin fiber and a continuous reinforcing fiber, which contain the polyamide resin or the polyamide resin composition of the present embodiment; and a nonwoven fabric composed of a thermoplastic resin fiber and a reinforcing fiber, which are composed of the polyamide resin or the polyamide resin composition of the present embodiment.

As molded articles, the molded articles can be used for automotive products such as films, sheets, pipes, gears, cams, various housings, rollers, impellers, bearing retainers, spring seats, clutch parts, chain tensioners, tanks (tank), wheels (wheel), connectors, switches, sensors, sockets (socket), capacitors, hard disk components, jacks, fuse holders, relays, coil bobbins, resistors, IC housings, LED reflectors, intake pipes, blowby tubes (blowby tubes), substrates for 3D printers, interior and exterior components of automobiles, components in engine rooms, cooling system components, sliding components, electrical components, and the like; surface-mounted components such as electric components, electronic components, surface-mounted connectors, sockets (sockets), camera modules, power supply components, switches, sensors, capacitor base plates, hard disk components, relays, resistors, fuse holders, bobbins, and IC cases; fuel tank cap, fuel tank, fuel delivery module, fuel cut-off valve, carbon canister, fuel piping and other fuel system components. The fuel-based component can be suitably used for various devices including engines using fuel such as gasoline and light oil, such as automobiles, tractors, rotary cultivators, weed cutters, lawn mowers, and chain saws. Details of the fuel system components can be found in paragraphs 0057 to 0061 of international publication No. 2012/098840, which are incorporated herein.

Examples

The present invention will be described more specifically with reference to examples. The materials, the amounts used, the ratios, the contents of the processes, the processing steps, and the like, which are shown in the following examples, may be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

When the measurement equipment or the like used in the examples is difficult to obtain due to stoppage of production or the like, other equipment having equivalent performance may be used for the measurement.

< raw materials >

p-BDEA: p-phenylenediethylamine was synthesized according to the following synthesis example.

Synthesis example of p-BDEA

P-phenylenediacetonitrile (manufacturer: tokyo chemical industry) is reduced under hydrogen atmosphere, and the obtained product is distilled and purified, thereby obtaining p-phenylenediethylamine. The purity was 99.7% as a result of analysis by gas chromatography.

m-BDEA: m-phenylenediethylamine was synthesized according to the following synthesis example.

Synthesis example of m-BDEA

M-phenyl-diacetonitrile (manufacturer: tokyo chemical industry) was reduced under a hydrogen atmosphere, and the resulting product was purified by distillation to obtain m-phenyl-diethylamine. The purity was 99.6% as a result of analysis by gas chromatography.

Isophthalic acid: the manufacturer: tokyo chemical industry

Terephthalic acid: the manufacturer: tokyo chemical industry

p-PDAA: p-phenylenediacetic acid, manufacturer: tokyo chemical industry

m-PDAA: m-phenylenediacetic acid, manufacturer: tokyo chemical industry

t-1,4-CHDA: trans-1,4-cyclohexanedicarboxylic acid, manufacturer: tokyo chemical industry

c-1,4-CHDA: cis-1,4-cyclohexanedicarboxylic acid, manufacturer: tokyo chemical industry

A blend of t-1,4-CHDA with c-1,4-cyclohexanedicarboxylic acid: trans-1,4-CHDA/cis-1,4-CHDA =36/64 mol%, manufacturer: riCA for Rixing

c-1,3-CHDA: cis-1,3-cyclohexanedicarboxylic acid, manufacturer: tokyo chemical industry

A mixture of t-1,3-CHDA and c-1,3-CHDA: trans-1,3-CHDA/cis-1,3-CHDA =38/62 mole%, manufacturer: tokyo chemical industry

MXDA: m-xylylenediamine, manufacturer: tokyo chemical industry

PXDA: p-xylylenediamine, manufacturer: tokyo chemical industry

Adipic acid: the manufacturer: tokyo chemical industry

Sebacic acid: the manufacturer: tokyo chemical industry

Hexamethylenediamine: 1,6-hexamethylenediamine, manufacturer: tokyo chemical industry

Nonane diamine: 1,9-nonanediamine, manufacturer: tokyo chemical industry

Decamethylenediamine: the manufacturer: 1,10-decamethylenediamine, manufacturer: tokyo chemical industry

Calcium hypophosphite: the manufacturer: fuji film and pure drug

Sodium acetate: the manufacturer: fuji film and pure drug

< example 1 >

Synthesis of Polyamide resin

A flat-bottomed test tube was charged with 0.0034 mol of p-BDEA (0.5585 g), 0.0034 mol of isophthalic acid (0.5648 g) and 7.0g of pure water, and the test tube was placed in a 20mL reaction tank equipped with a thermometer, a pressure gauge and a pressure regulating valve. Then, nitrogen substitution was sufficiently performed to return the pressure inside the reaction tank to normal pressure, and then the pressure regulating valve was closed. The autoclave was heated with an aluminum heater, and the internal pressure of the autoclave was maintained at 1.9MPa and 210 ℃ for 20 minutes, and then at 2.8MPa and 230 ℃ for 40 minutes. Subsequently, the temperature was raised to 260 ℃ and the pressure regulating valve was slightly opened, and water was taken out from the pressure regulating valve while the pressure was reduced to normal pressure for 30 minutes. Thereafter, the reaction tank was heated to the melting point +10 ℃ while appropriately withdrawing water from the pressure regulating valve, and held for 10 minutes. After the reaction tank was cooled to room temperature, the test tube was taken out to obtain a polyamide resin.

< determination of melting point (Tm), glass transition temperature (Tg) and enthalpy change of crystallization at reduced temperature (. DELTA.H) >

The melting point, glass transition temperature, and change in enthalpy of crystallization at a reduced temperature (Δ H) of the synthesized polyamide resin were measured by Differential Scanning Calorimetry (DSC). DSC measurement was carried out in accordance with JIS K7121 and K7122. The synthesized polyamide resin was pulverized and charged into a measuring pan of a differential scanning calorimeter using a differential scanning calorimeter, and heated to a melting point +20 ℃ shown in table 1 at a temperature rise rate of 10 ℃/min under a nitrogen atmosphere, and immediately after the temperature rise, the measuring pan was taken out and pressed against dry ice to be quenched. And then measured. The measurement conditions were: the temperature was raised to the melting point +20 ℃ shown in Table 1 at a temperature raising rate of 10 ℃/min and held for 5 minutes, and then the temperature was lowered to 100 ℃ at a temperature lowering rate of-5 ℃/min to determine the melting point (Tm) and the glass transition temperature (Tg). Further, the change in enthalpy (. DELTA.H) (unit: J/g) during the temperature-decreasing crystallization was also determined.

As the differential scanning calorimeter, "DSC-60" manufactured by Shimadzu corporation was used.

The units of melting point in degrees Celsius, glass transition temperature in degrees Celsius, and the units of change in enthalpy of crystallization at decreasing temperature (. DELTA.H) are expressed in J/g.

Mass reduction rate

The mass reduction rate of the obtained polyamide resin (in the form of powder) was measured by thermal mass analysis.

The obtained polyamide resin was charged into a measuring pan of a thermal mass analyzer, and heated to a melting point +25 ℃ at a temperature rise rate of 10 ℃/min under a nitrogen atmosphere, followed by heating for 30 minutes. The mass reduction rate was measured by the following equation.

Mass reduction rate = { [ (mass of polyamide resin when heated to melting point-50 ℃) (mass of polyamide resin when heated at melting point +25 ℃ for 30 minutes) ]/(mass of polyamide resin when heated to melting point-50 ℃) } × 100

The unit of mass reduction is expressed in%.

As the thermal mass analyzer, "DTG-60" manufactured by Shimadzu corporation was used.

Air leakage

Among the components contained in the obtained polyamide resin, a component having a low molecular weight, particularly a cyclic compound (cyclic monomer) comprising 1 molecule of each of a diamine and a dicarboxylic acid is likely to volatilize during molding and to cause gas leakage. Therefore, the amount of the cyclic monomer was measured by Gel Permeation Chromatography (GPC) as an evaluation of the gas leakage property of the polyamide resin.

As the GPC analysis device, "HLC-8320GPC" manufactured by Tosoh corporation was used. As the column, TSK gel Super HM-H (manufactured by Tosoh Co., ltd.), hexafluoroisopropanol (2 mmol/L solution of sodium trifluoroacetate) was used as a solvent, and PMMA was used as a standard substance.

GPC was conducted at 40 ℃ and a sample concentration of 0.3g/L for the obtained polyamide resin, and the area of peaks of the cyclic monomer and the higher molecular weight component was measured based on a GPC chart of the obtained polyamide resin.

Gas leakage = { (area of cyclic monomer)/(area of cyclic monomer + area of component having higher molecular weight than cyclic monomer) } × 100

The unit of air leakage is expressed in (%). A lower value of the gas leakage property indicates a tendency that gas leakage is more difficult to occur.

< example 2 >

In example 1, the same procedure was followed except that the dicarboxylic acid was changed as shown in Table 1.

< example 3 >

In example 1, the dicarboxylic acid was changed as shown in table 1, and the other steps were carried out in the same manner.

< example 4 >

< example 5 >

In example 1, the dicarboxylic acid and diamine were changed as shown in Table 1, and the other operations were carried out in the same manner.

< example 6 >

In example 1, the dicarboxylic acid and diamine were changed as shown in Table 2, and the other operations were carried out in the same manner.

< example 7 >

In example 6, the same procedure was followed except that the dicarboxylic acid was changed as shown in Table 2.

< example 8 >

In example 6, the same procedure was followed except that the dicarboxylic acid was changed as shown in Table 2. Note that t-1,3-CHDA and c-1,3-CHDA were a mixture of t-1,3-CHDA and c-1,3-CHDA (manufacturer: tokyo chemical industry).

< example 9 >

< example 10 >

In example 6, the same procedure was followed except that the dicarboxylic acid was changed as shown in Table 2. Note that t-1,4-CHDA and c-1,4-CHDA were a mixture of t-1,4-CHDA and c-1,4-CHDA (manufacturer: rica).

< example 11 >

In example 6, the kind and amount of dicarboxylic acid were changed as shown in Table 2, and the rest was conducted in the same manner.

< example 12 >

In example 11, in addition to the diamine and the dicarboxylic acid, 0.5mg of calcium hypophosphite (0.02 mass% in terms of phosphorus concentration in the polyamide resin), and 0.3mg of sodium acetate were added, and the rest was performed in the same manner.

< reference example 1 >

In example 1, the dicarboxylic acid and the diamine were changed as shown in Table 3, and the rest was carried out in the same manner.

< reference example 2 >

In reference example 1, the kind and amount of dicarboxylic acid were changed as shown in Table 3, and the rest was carried out in the same manner.

< reference example 3 >

< reference example 4 >

< reference example 5 >

[ Table 1]

[ Table 2]

[ Table 3]

From the above results, it is understood that the polyamide resin of the present invention has a high melting point and a high glass transition temperature. Further, Δ H is high and moldability is excellent. In addition, the mass reduction rate is small. And also has excellent gas leakage properties.

< example 13 >

In example 11, the amounts of diamine and dicarboxylic acid were changed to 20 times, the amount of pure water added was changed to 9.6g, and the capacity of the reaction tank was changed to 200mL, and the rest was performed in the same manner. A polyamide resin having the same performance as in example 11 was obtained.

< examples 20 to 25 resin compositions containing an antioxidant

The antioxidants described in table 4 were weighed out in each 100 parts by mass of the polyamide resin (p-BIC) obtained in example 13, dry-blended, and then melt-kneaded using a twin-screw extruder (Process 11 parallel twin-screw extruder, manufactured by Thermo Fisher Scientific corporation) to obtain resin composition pellets. The temperature of the extruder was set to 320 ℃.

The polyamide resin obtained in example 13 and the resin composition pellets obtained in examples 20 to 25 were evaluated as follows.

< weight average molecular weight after Heat aging, and conservation ratio of weight average molecular weight >

It is generally known that various physical properties such as mechanical strength and melt viscosity of a polymer are related to a weight average molecular weight when the composition and conditions are the same except for the weight average molecular weight. In particular, the higher the weight average molecular weight, the higher the value tends to be, and the higher the retention of the weight average molecular weight after heat aging, the higher the retention of the mechanical strength tends to be.

The obtained pellets were pulverized, charged into an aluminum cup, stored at 120 ℃ for 7 days using a shielded thermostat (SPH-202, manufactured by ESPEC corporation), and the weight average molecular weights before and after storage were measured. The retention of the weight average molecular weight was calculated by the following formula.

Weight average molecular weight retention (%) = (weight average molecular weight after storage/weight average molecular weight before storage) × 100

The weight average molecular weight was determined from a standard polymethyl methacrylate (PMMA) conversion value measured by Gel Permeation Chromatography (GPC). As the column, 2 columns packed with a styrene-based polymer as a filler were used, hexafluoroisopropanol (HFIP) having a sodium trifluoroacetate concentration of 2mmol/L was used as a solvent, the resin concentration was 0.02 mass%, the column temperature was 40 ℃ and the flow rate was 0.3 mL/min, and the measurement was performed by a refractive index detector (RI). In addition, calibration curves were determined by dissolving 6 grades of PMMA in HFIP.

Color phase

The color of the heat-aged sample was visually observed, and the samples were classified into A to D in the order of increasing change. A is the color change minimum and the appearance is excellent, and D is the color change maximum and the appearance is poor. Evaluation was performed by 5 experts and was determined by majority decision.

A: the color of the heat-aged sample was white to pale yellow

B: the color of the heat aged sample was light yellow

C: the color of the heat-aged sample was yellow

D: the color of the heat-aged sample was brown

[ Table 4]

The components shown in table 4 are as follows.

Irganox1098: hindered phenol antioxidant manufactured by BASF

NORAC White: amine antioxidant manufactured by Dai-Nei-Tao-Kagaku chemical industries Ltd

ADK STAB PEP-36: phosphorus antioxidant manufactured by ADEKA Inc

Sumilizer TP-D: sulfur antioxidant, manufactured by Sumitomo chemical Co Ltd

And (2) CuI: cuprous iodide, inorganic antioxidant, manufactured by Nippon chemical industries Ltd

KI: inorganic antioxidant, fuji film and Wako pure chemical industries

As is clear from table 4 above, the incorporation of an antioxidant reduced the rate of change in the weight average molecular weight after the heat preservation test and exhibited excellent thermal stability (examples 20 to 25) as compared with the case where no antioxidant was incorporated (example 13). Further, by using the primary antioxidant and the secondary antioxidant together, particularly by using the inorganic antioxidant together, the rate of change in the weight average molecular weight after the heat preservation test can be further reduced.

Further, by using a hindered phenol antioxidant, the hue after the heat preservation test is also excellent.

< example 30 resin composition blended with flame retardant >

The flame retardant and the flame retardant auxiliary described in table 5 were respectively weighed against 100 parts by mass of the polyamide resin (p-BIC) obtained in example 13, dry-blended, and then melt-kneaded using a twin-screw extruder (Process 11 parallel twin-screw extruder, manufactured by Thermo Fisher Scientific corporation) to obtain resin composition pellets. The temperature of the extruder was set to 320 ℃.

The polyamide resin obtained in example 13 and the resin pellet obtained by the above-mentioned production method were dried under vacuum at 200 ℃ for 4 hours, and then injection-molded using a C, mobile type injection molding machine, a Sellbic corporation, under conditions of a cylinder temperature of 325 ℃ and a mold temperature of 150 ℃. The molded sheet thus obtained was held between glass plates and annealed at 260 ℃ for 1 hour under vacuum to thereby mold a test piece for UL94 test having a length of 125mm, a width of 13mm and a thickness of 3.2 mm. The results are shown in table 5 below. V-0 is the most excellent in flame retardancy.

[ Table 5]

Composition (I)	Unit of	Example 30	Example 13
				p-BIC	Parts by mass	100	100
Exolit OP 1312	Mass portion of	27.4
				Flamtard S	Parts by mass	9.6
UL94 burn test	-	V-0	V-2

The components shown in table 5 are as follows.

Exolit OP 1312: phosphinic acid metal salt flame retardant manufactured by Clariant corporation

Flamitard S: flame retardant aid, tin zinc oxide, manufactured by Nippon light metals Co., ltd

From the above results, it is understood that the flame retardancy is improved by compounding the flame retardant.

< examples 40 and 41 nucleating agent-compounded resin compositions >

The nucleating agents shown in Table 6 were weighed out in each 100 parts by mass of the polyamide resin (p-BIC) obtained in example 13, dry-blended, and then melt-kneaded using a twin-screw extruder (a parallel Process11 twin-screw extruder, manufactured by Thermo Fisher Scientific Co., ltd.) to obtain resin composition pellets. The temperature of the extruder was set to 320 ℃.

The polyamide resin obtained in example 13 and the resin pellets obtained by the above-described production method were subjected to DSC measurement in the same manner as in example 1, tg and the temperature-raised crystallization temperature Tch were measured, and Tch-Tg, which is the temperature difference between Tch and Tg, was calculated. The smaller the Tch-Tg, the higher the crystallization rate and the better the productivity in injection molding. The unit of Tch-Tg is expressed in ℃ C.

[ Table 6]

Composition (A)	Unit of	Example 40	Example 41	Example 13
					p-BIC	Mass portion of	100	100	100
SG2000	Mass portion of	3
					PAOG-2	Mass portion of		3
Tch-Tg	℃	56	59	62

The components shown in table 6 are as follows.

SG2000: ultrafine talc powder, manufactured by Nippon talc Co Ltd

PAOG-2: flat Talc manufactured by Japan Talc

Claims

1. A polyamide resin comprising a diamine-derived structural unit and a dicarboxylic acid-derived structural unit,

50 mol% or more of the diamine-derived structural unit is a structural unit derived from p-phenylenediethylamine,

65 mol% or more of the dicarboxylic acid-derived structural units are aromatic dicarboxylic acid-derived structural units.

2. The polyamide resin according to claim 1, wherein more than 95 mol% of the structural units derived from a dicarboxylic acid are structural units derived from an aromatic dicarboxylic acid.

3. The polyamide resin according to claim 2, wherein 90 mol% or more of the structural units derived from an aromatic dicarboxylic acid are structural units derived from an aromatic dicarboxylic acid selected from isophthalic acid, terephthalic acid, and phenylenediacetic acid.

4. The polyamide resin according to claim 2, wherein 90 mol% or more of the structural units derived from an aromatic dicarboxylic acid are structural units derived from an aromatic dicarboxylic acid selected from isophthalic acid and phenylenediacetic acid.

5. The polyamide resin according to claim 1, wherein 65 to 97 mol% of the structural units derived from a dicarboxylic acid are structural units derived from an aromatic dicarboxylic acid, and 3 to 35 mol% are structural units derived from an alicyclic dicarboxylic acid.

6. The polyamide resin according to claim 1, wherein 75 to 97 mol% of the structural units derived from a dicarboxylic acid are structural units derived from an aromatic dicarboxylic acid, and 3 to 25 mol% are structural units derived from an alicyclic dicarboxylic acid.

7. The polyamide resin according to claim 5 or 6, wherein 90 mol% or more of the structural units derived from an alicyclic dicarboxylic acid are structural units derived from an alicyclic dicarboxylic acid represented by the following Formula (FA),

formula (FA)

HOOC-(CH ₂ ) _n -alicyclic structure- (CH) ₂ ) _n -COOH

In the Formula (FA), n represents 0, 1 or 2.

8. The polyamide resin according to claim 5 or 6, wherein 90 mol% or more of the structural units derived from an alicyclic dicarboxylic acid are structural units derived from cyclohexanedicarboxylic acid.

9. The polyamide resin according to claim 5 or 6, wherein 90 mol% or more of the alicyclic dicarboxylic acid-derived structural units are structural units derived from a mixture of trans-form cyclohexanedicarboxylic acid and cis-form cyclohexanedicarboxylic acid.

10. The polyamide resin according to any one of claims 1 to 9, wherein more than 95 mol% of the diamine-derived structural unit and the dicarboxylic acid-derived structural unit are structural units having a cyclic structure.

11. The polyamide resin according to any one of claims 1 to 10, wherein the polyamide resin has a melting point of 300 ℃ or higher as measured by differential scanning calorimetry.

12. The polyamide resin according to any one of claims 1 to 11, wherein the polyamide resin has a glass transition temperature of 100 ℃ or higher as measured by differential scanning calorimetry.

13. A resin composition comprising the polyamide resin as claimed in any one of claims 1 to 12.

14. The resin composition of claim 13, further comprising an antioxidant.

15. The resin composition of claim 14, wherein the antioxidant comprises a primary antioxidant and a secondary antioxidant.

16. The resin composition of claim 14 or 15, wherein the antioxidant comprises an inorganic antioxidant.

17. The resin composition according to any one of claims 13 to 16, further comprising a flame retardant.

18. The resin composition according to any one of claims 13 to 17, further comprising a nucleating agent.

19. A molded article formed from the resin composition according to any one of claims 13 to 18.